High resilience fire retardant urethane foam

Claim 1

In the process of producing a cold cured, stable, fire retardant, high resilience polyether urethane foam having a sag factor of at least 2.2 by reaction of an unhalogenated polyether polyol and, as an organic isocyanate reactant, tolylene diisocyanate or polymethylene polyphenyl polyisocyanate of the formula: ##STR2## wherein n is an integer predominantly of from 0 to 1 inclusive, or mixtures of said tolylene diisocyanate and said polymethylene polyphenyl polyisocyanate, in the presence of a blowing agent and catalyst; the improvement that comprises incorporating therein as a chain-extending agent and additional reactant, 2,3-dibromo-2-butenediol-1,4 in an amount by weight of said unhalogenated polyol of 3 to 9 percent; the resulting polyether urethane foam containing less than 5 percent of polymerized isocyanurate by weight of reactant isocyanate.